Browsing by resource type "conference object"
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- 2ª Conferência Internacional 3MG - Montanhas Mediterrânicas e Património GeológicoPublication . Associação Geopark EstrelaA conferência “3MG”, tem como principal objetivo trazer ao território do Geopark Estrela, especialistas em gestão de espaços de Montanha, Geoparks Mundiais da UNESCO, Património Geológico, Geoturismo e Educação, com o objetivo de discutir novos resultados de investigação e as melhores práticas, e como aplicá-los às montanhas. Pretende-se que esta conferência seja um fórum interdisciplinar aberto, de partilha de experiências, capaz de elencar oportunidades para a resolução dos problemas inerentes a territórios de montanha. Pretende-se uma participação ativa de professores do Ensino Básico e Secundário, dando a conhecer a geodiversidade da Estrela, numa clara relação com a biodiversidade e com a cultura enquanto recurso educativo.
- 3D Simulations of Droplets Impacting Liquid Films: Crown Parameters MeasurementsPublication . Vasconcelos, Daniel; Ribeiro, Daniela; Silva, R. D.; Barata, Jorge M MThe 3D incompressible Navier-Stokes equations are coupled with the CLSVOF method and employed to numerically simulate the phenomena of single droplet impact onto liquid films. A solution-adaptive mesh refinement tool, based on the gradient of the volume fraction scalar, is adopted in order to reduce computational cost. Three different fluids are taken into account: 100% jet fuel and 75%/25% and 50%/50% of jet fuel and biofuel, respectively. Quantitative analysis of the crown height and outer diameter is performed for different impact conditions, such as the influence of the impact velocity and dimensionless thickness, between experimental and numerical results, and the qualitative analysis includes the occurrence of splashing and overall crown evolution. Numerical results show that the crown outer diameter measurements are in good agreement with the experimental cases, presenting a slight discrepancy for the lower liquid film thickness of h*= 0.2. The crown height measurements are under-predicted for the current model, maintaining a similar trend for dimensionless thicknesses of h*= 0.5 and h*= 1 while, for the lower thickness, the crown disintegrates at earlier stages. The crown curvature and rim instabilities exhibit significant differences, and the splashing phenomenon occurs for both the experimental and numerical outcomes.
- aBEIRAr – Uma Biblioteca do Ensino Superior num projeto de Ciência CidadãPublication . Pessoa, Paulo; Pinto, SandraO Projeto de Ciência Cidadã – aBEIRAr – nasce de uma convergência de objetivos comuns entre diferentes parceiros que estão inseridos num território de montanha e no interior de Portugal. A valorização deste território constituiu o mote para que se desse início à criação e desenvolvimento do projeto, tendo sempre em conta o fundamental e imprescindível envolvimento do cidadão, entre o saber ancestral e o conhecimento científico. Haverá melhor forma de valorizar o território, do que cruzar os saberes e envolver os que nele vivem, ao mesmo tempo que se impulsiona a inovação tendo em conta a idiossincrasia territorial? É este o mote que sustenta o projeto aBEIRAr: participação do cidadão, reconhecimento do saber ancestral e científico para uma inovação efetiva e sustentável destes territórios tantas vezes esquecidos e pouco valorizados.
- Abstract Book 15th Geoparks ConferencePublication . Castro, Emanuel; Firmino, Gisela; Gomes, Hugo; Cezar, Lucas; Sá, Artur; Silva, Elisabeth; Fernandes, Magda; Vieira, Gonçalo; Loureiro, Fábio; Patrocínio, Filipe; Castel-Branco, João; Azevedo, PatríciaThe UNESCO Global Geoparks (UGGps) are territories of science, education and culture. These develop holistic approaches to sustainable development aiming to create new tools that can reinforce endogenous values and empower local communities. The Estrela Aspiring Geopark was created and implemented based on this reality and principles. Since the beginning, sustainable development of the territory was a priority, considering the uniqueness of the Estrela Mountain area and the importance of the protection and valorisation of its endogenous potential, with emphasis on the geological heritage.
- Advanced CaZrO3-MgO Ceramic Compositions for High Responsability ApplicationsPublication . Nunes-Pereira, João; Pereira Silva, A; Pena, Pilar; Baudin, CarmenThe development of new advanced materials for harsh environment operation conditions, such as high temperature, wear and severe erosion and corrosion, is of growing interest, namely for transport and energy industries, due to the ecological and energetic current concerns on a global scale. Particularly, in aerospace industry the increase of working temperature of engines and turbines combined with weight reduction will give rise to higher thrust and lower fuel consumption and consequently less emissions. [...]
- Advancements in High-Frequency Antenna Design: Integrating Photonic Crystals for Next-Generation Communication TechnologiesPublication . Bagheri, Nila; Velez, Fernando J.; Peha, JonCentral to this study is the introduction of a pioneering photonic crystal-based microstrip patch antenna array with high gain. Engineered to meet the demands of evolving wireless communication technologies, this novel antenna system leverages Photonic Band Gap (PBG) structures. A fractal microstrip patch antenna, operating within the E-W-F band, is designed and simulated using the High-Frequency Structure Simulation (HFSS) software. With an operational frequency spanning 60.15 GHz to 120 GHz and a resonant band at 64.80 GHz, the antenna achieves a peak gain of 10.50 dBi within the obtained bandwidth. In this study, we selected Rogers RT/Duroid 5880 as the substrate material for our antenna, capitalizing on its unique properties to achieve superior functionality in high-frequency applications. One of the advantages of RT/Duroid 5880 is its exceptionally low dielectric constant (Ɛr = 2.2). This property is paramount for high-frequency antennas, as a lower dielectric constant facilitates improved signal propagation characteristics. The result is reduced signal loss and enhanced impedance matching, contributing to the overall efficiency of the antenna. The mechanical machinability of RT/Duroid substrates, including RT/Duroid 5880, adds another layer of advantage. The material can be easily cut, sheared, and machined to shape, streamlining the manufacturing process, and allowing for precise customization of the antenna design. In addition, by creating air hole in substrate reduce the dielectric constant, the introduction of air holes can decrease the effective dielectric constant of the material. As a lower dielectric constant results in a slower wave propagation speed, a reduction wavelength and a more compact antenna design may result. The presence of air holes or a photonic crystal structure can modify the electromagnetic properties of the substrate, potentially leading to enhanced bandwidth characteristics of broadband antennas.
- Aerodynamic Breakup of a Single Droplet due to a Crossflowed AirstreamPublication . Carrolo, Gabriel Alexandre da Costa; Ribeiro, Daniela; Barata, Jorge M M; Silva, A. R. R.The main breakup regimes are visualized and studied with the help of a high-speed camera and a continuous jet of air, provided by a wind tunnel, is used to transition the droplet into the various stages of secondary atomization. The use of Jet Fuel and Biofuel mixtures is the focal point of this study. All the known regimes are encountered and each transitional We is calculated. The variation of We due to Oh is described, in addition to the comparison between We number thresholds and correlations existent in the literature for each regime transition. The influence of these numbers on the dimensionless characterization of time and later the maximum cross stream diameter is shown. Finally, a correlation for the temporal evolution of the drops’ cross stream diameter for all regimes, assuming its deformation is not a linear function of time, is proposed.
- Air Budjet: a VTOL virtual operator company in PortugalPublication . Duarte, Manuel Mendes; Baltazar, Maria Emilia; Silva, J.Creation of sustainable transportation service for a new and virtual airline company that uses VTOL aircraft in order to increase mobility and flexibility in Portugal. This study started with the VTOL concepts, peripherally and accessibility, and business models and plans reviews. The air service characterization was then carried out using localization and trajectory optimization algorithms, thus allowing to elaborate two applications (software): one for clients to book their flights and another that compiles flight's data booked by clients and optimizes flights routes/trajectories. With this study, it is possible to depict the viability of the economic-financial results of the new virtual company and the application development results with the optimized trajectories. The development of this air service will increase accessibility and mobility in all regions of Portugal and companies that cannot afford the costs of executive aviation, too. In order to facilitate the booking of the flights, an application was created for the client in order to optimize the company costs related to this air service, and thus to make the cost of a trip more appealing; a second application was elaborated that optimizes the trajectories of the aircraft.
- Airports Catchment Area Size Definition: a Portuguese Case StudyPublication . Baltazar, Maria Emilia; Silva, JorgeThe definition of the Catchment Area of an airport is very broad and current literature suggests doing it in combination with certain pre-defined criteria: the assessment of the impact or effectiveness of a certain airport, or from the perspective of competition between airports. This paper aims to assess the validity of the hinterland defined by the Portuguese airport manager, ANA - Aeroportos de Portugal. A case study was developed involving the three main national airports: Lisbon (LIS), Oporto (OPO) and Faro (FAO). ANA defined the hinterland of each airport. Thus, a survey was developed to the companies located within the hinterland of every airport aiming to understand the existence of any relationship between them and the closest airport. We followed a stratified sample method to determine the size of the survey. We only considered import and export companies with the highest business volumes. Data analysis was performed using GIS (Geographic Information System), that is a software, spatial data and computational procedures system that enables and facilitates the analysis, management and representation of space and phenomena that occur in it. We collected a total of 243 surveys. The main conclusion of the study was that the calculation of an airport’s hinterland based exclusively on the travel time or distance is, potentially, misleading. It is proposed the use of other factors. The validity of such a method and practice raises some doubts. The actual distribution of economic activities and population is ignored as well as the mutual influence of several airports. Further research is now needed to calculate airports actual influence.
- Alkali-activation of tungsten mining waste mud blended with waste glass: reactivity, performance and innovative applicationsPublication . Gomes, João Castro; Magrinho, Manuel; Sedira, Naim; Beghoura, Imed; Humbert, Pedro; Manso, Maria; Fernandes, Ana; Silva, RafaelMines and quarries waste accounts for about 29% of the total generated waste from industrial processes and households in Europe. The reuse of mud tailings as precursor materials for alkali-activated binders and applications are very promising from a technical and environmental point of view. The aim of the present study was to develop added-value solutions to reutilize tungsten mine mud tailings in alkali activated materials. Some potential uses of these new materials obtained from alkali-activation of tungsten mud waste and other precursor materials, as well incorporating expanded granulated cork, such us a high energy efficient panel for a vegetated surface and a foamed lightweight brick wall, are presented.